Every year accidents happen in regard to small children, pets and others, forgotten in vehicles. Forgetfulness occurs, among others, due to the driver's routine change, who follows a pattern of actions without remembering the presence of a passenger in the vehicle and, therefore, leaving the vehicle without taking the passenger away.
In order to prevent this kind of accident, several systems have been developed to remind the driver about the presence of occupants. Such systems generally use sensors installed on the vehicle seats, which detect directly the presence of passengers.
Solutions are already known in the art, which involve addition of components to the vehicle, generating increasing cost and the impossibility of application in the entire range of output. These solutions present results using direct measurement, which is performed in the seat by different components/sensors.
Among said known solutions, can be cited those disclosed by the following documents: U.S. Pat. No. 7,701,358 and US 2004/0113797, wherein thermal sensors are attached to the vehicle seats; U.S. Pat. No. 7,123,157, US 2014/0184404, US 2006/0044126 and US 2007/0268119, wherein weight/pressure sensors are attached to the vehicle seats; U.S. Pat. No. 7,325,870 and US 2007/0075575, wherein locking sensors are attached to the fasten seat belt buckle on the back seat of the vehicle; in addition, the documents U.S. Pat. No. 8,643,493 and US 2009/0079557, disclose sensors carried by the driver and/or child on key chains or similar. Other solutions, for the same purpose, are identified in U.S. Pat. Nos. 8,232,874 and 8,063,788 documents, wherein the sensors are coupled directly in the baby carrier basket and the document CN 201828790, discloses sensors which detect the passenger presence by voltage variation. Finally, documents U.S. Pat. No. 8,892,302, US 2008/0088426 and U.S. Pat. No. 8,816,845 which disclose the detection of an occupant presence at the back seat, but no mention is made to the means such detection is performed.
US 2013/0009766 teaches an alarm system for persons or objects forgotten inside a vehicle. However, the proposed system just warms the driver that a previously informed item was forgotten after the system detects the driver left the vehicle.
US 2012/0050021 teaches a person, pet or objects detection system for alerting the driver. The identification of a person, pet or object presence is made by a complex combination of vibration, sound and temperature sensor.
All the above patents are related to monitoring systems performed by direct detection, all of them incurring in implementation costs and changes in the vehicle.
Finally, U.S. Pat. No. 8,493,201 document discloses a system for identifying a casual forgetfulness of an occupant at the back seat of a vehicle, based on both the opening of one of the rear doors and implementation of a button to disable the system, this button provided in the rear part of the passenger compartment. More particularly, the logic for identifying the possible presence of an occupant at the back seat is based on the door opening time relative only to one of the rear doors of the vehicle, while an alarm is activated after the ignition and turning off of the vehicle have been detected. Said alarm continues operating, that is sounding, until a respective rear button, not accessible to the occupants of the front seats of the vehicle, is pressed.
Despite the concept aimed at detecting the rear door opening time is interesting, the implementation of the disclosed system reveals serious operational problems. First, if the driver has placed an object at the back seat and the car dies, the act of restarting said vehicle will cause the alarm activation and therefore the need for the driver to leave his seat, open the rear door and press one of the buttons located on the rear frames of the vehicle. Similarly, if the driver is with his son at the back seat and parks the vehicle in front of the school waiting for picking his another child up, this action also will cause the alarm activation and the need for the driver to leave his seat, open the rear door and press one of the rear buttons in order to turn off the sonorous alarm, probably waking up the child who is inside the vehicle.